Traumatic brain injury (TBI) is an acquired neurological disorder that can cause long-lasting disability with limited treatment options. Therefore, preventative strategies must be emphasized in high-risk activities to reduce the individual and societal burden of this pervasive injury. Bicycle activities account for 20% of all sports-related TBI, with 42,000 annual injuries in the US. In an effort to alleviate the incidence and severity of these head injuries, helmet usage is now recommended, and in some states mandatory. However, contemporary bicycle helmets are not designed to mitigate rotational head acceleration, which is a clear physical mechanism of TBI. A novel helmet using High Impact Velocity Engineering (HIVE) technology is therefore proposed that combines recent advances in material science with an innovative suspension technique to provide superior energy absorption in a lightweight and cost-effective design. A key innovation of the HIVE helmet is that its structural properties behave similar to a torsional spring and damper, and thus enable the HIVE helmet to attenuate severe rotational head accelerations. The STTR Phase I delivered conclusive evidence on the feasibility of HIVE technology. HIVE prototype helmets yielded up to 46% reduction in rotational head acceleration and up to 44% reduction in predicted TBI risk compared to standard bicycle helmets. The aim of this STTR Phase II research and development strategy is to formally optimize the performance of HIVE technology by combining computational modeling and physical validation. The optimized HIVE technology will be translated into a commercially viable helmet design. The resulting HIVE helmets will be evaluated in vertical and oblique impacts to quantify performance improvements compared to standard helmets. If successful, the final HIVE helmet design can readily be commercialized to offer advanced head protection for bicyclists and to reduce the incidence and severity of bicycle-related TBI.